BECOME COMPETENT AT NETWORKING
A computer network, commonly just called a network, is a system of interconnected computers (and devices) that operate interactively. Any number of computers may be connected into a network, from two to dozens, hundreds, thousands or even millions. Networks typically include other devices such as printers, external hard drives, modems and routers, etc. Nearly everyone involved with computers at any level now requires knowledge and skills with networks computer systems.
Gain the skills and competancy you need in Networking with this course. Studies include: networking introduction, topology, architecture and transmission media; components and hardware; design and planning; upgrading; basic TCP/IP Services and Applications and more.
Lesson Structure
There are 10 lessons in this course:
- Networking Terms, Concepts and Standards
- What is a network
- History of networks
- Network hosts and backbones
- Access vs core networks
- Internet backbone
- What is a host
- Types of computer networks
- Local area network (LAN)
- Wide area network (WAN)
- Home networking and Wireless local area networks
- Types of LANs
- LAN topology
- Wireless networking (Wi Fi)
- Hardware for a basic network
- Network cards
- Network cable
- Hubs and switches
- Routers
- Network standards
- ISO
- Network Topology, Architecture and Transmission Media
- Physical vs. local topology
- Design considerations
- Physical topologies: star, bus, ring, tree, mesh
- Logical topologies
- Architecture of a network
- Transmission media
- Cost of a network
- Band width
- Band use
- Multiplexing
- Attenuation
- Electromagnetic interference
- Network Components and Hardware
- Repeater
- Switch
- Hub
- Bridge
- Router
- Server
- Modem
- Short haul modems
- Firewall hardware
- Network Design and Planning
- Evaluating needs of an organisation
- Applications
- Users
- Network services
- Security of the network
- Growth planning
- Designing a logical network
- Communicating effectively with clients
- Network Upgrading and Project Management
- Why upgrade a network
- Is it time to upgrade
- What are the new requirements
- Planning an upgrade: prioritise, budget, evaluate
- Network Protection and Maintenance
- Information security
- Network attacks
- Man in the middle attack
- Replay attack
- Denial of service attack
- Distributed denial of service attack
- Attackers
- Internal security
- Password security
- File and directory permissions
- Educating users
- External security
- Firewalls
- Intrusion detection systems
- Security zones
- Virtual LAN's
- Understanding Network Connecting Options
- Dial up connections
- DSL connections
- ADSL connections
- ADSL+2 connections
- Cable connections
- Leased line connections
- Satellite
- Installation and Configuration of Network
- Network installation process
- Cabling the network
- Router configuration
- Server configuration
- Multiple equipment configuration
- Testing the configuration
- Basic TCP/IP Services and Applications
- TCP/IP suite
- HTTP
- SMTP/POP3
- Telnet
- FTP
- DNS
- NNTP
- Troubleshooting Tools for TCP/IP Networks
- Troubleshooting techniques
- Troubleshooting tools
- Ping
- Traceroute
- NSlookup
- Hostname
Each lesson culminates in an assignment which is submitted to the school, marked by the school's tutors and returned to you with any relevant suggestions, comments, and if necessary, extra reading.
Aims
- Discuss the history and key developments in networking.
- Describe the main networking models, terminology and standards.
- Explain the different topologies, architectures and transmission media in computer networks.
- Explain the physical components within a network and how individual components connect to each other.
- Evaluate the needs of the organisation and design a logical network.
- Discuss reasons for network upgrade and techniques for managing a network upgrade.
- Explain the importance of network protection to prevent downtime and preserve valuable data.
- Identify and compare various connection options like dial-up connections and dedicated connections.
- Describe the installation process and configurations for networking.
- Describe the TCP/IP suites of utilities generally used by end users.
What is a Network? How is is put together, and what can it do?
Networks have evolved significantly over the past few years. However, each network still follows sound network design fundamentals. When an organisation decides to build a network, it would expect that network to be reliable, secure and fast, and provide efficient communication, thus improving their business.
Each organisation, regardless of how small or large it is, needs to understand the needs it has prior to developing a network. Therefore, there is no point in purchasing cabling, networking equipment (routers, switches, hubs, etc.), or computers before performing the planning phase, whereby the organisation needs are assessed. Different organisations have got different needs, and thus will have different network components and network designs. A small organisation for example would have no remote sites, or only a few of them, whereas a large organisation would have many distributed sites, and these needs to be catered for in the initial planning phase.
Therefore, the first step that needs to be done is getting to know what the network needs to accomplish. Some of the critical questions that need detailed answers are:
- What added functionality will the network present to the organisation?
- How many computers are there on the network?
- What is the organisation’s budget for running this project?
- How much storage space is required?
- What applications are going to be used on the network?
- How much bandwidth is required for the network?
- What types of cabling or transmission media are needed?
- What is the expected rate of expansion at the company with regards to users and resources?
- Is the network going to be connected to the internet?
- Will users require to login remotely to the network, via virtual private network (VPN)?
Types of Computer Networks
There are many types of computer networks, often defined by the types of users, the purpose of the network, or most commonly, the size and configuration of the network connections and devices attached to it.
Through the years of network development, various names for networks have been used and which describe some feature of the network. The most common network names, which are still in use today, are:
- LAN – Local Area Network
- WAN – Wide Area Network
- WLAN – Wireless Local Area Network
LAN (Local Area Network)
A LAN is a network of computers and devices connected over relatively short distances, for example within a room, a home, a small office or building, a school or other small business or organisation. Sometimes a single building may contain a few small LANs (perhaps one per room or work group), or a group of nearby buildings may be connected to form a LAN. In the TCP/IP network protocol, a LAN is often, but not always, implemented as a single IP subnet. (The TCP/IP protocol is explored in later Lessons.)
In addition to operating in a limited space, LANs are also typically owned, controlled and managed by a single business or organisation. They often use certain connectivity technologies, typically Ethernet and Token Ring (network technologies which are discussed in later Lessons).
WAN (Wide Area Network)
As the name suggests, a WAN covers a large physical area, and is usually collection of interconnected LANs. The Internet is the largest WAN and which spans the entire planet.
Connections within a WAN may be coaxial or fibre optic cabling, ISDN lines, radio waves or satellite links. Server software is needed for operating a large network. The server software controls the data communications within the network, and manages access to the individual devices and services offered on the network.
Network routers connect LANs to a WAN. In IP networking, the router maintains both a LAN address and a WAN address. A WAN differs from a LAN in several important aspects. Most WANs, like the Internet, are not owned by any one business or organisation, but rather are a collective of interested parties, with distributed ownership and management. WANs tent to use technologies like ATM, Frame Relay and X.25 for connectivity over the longer distances (discussed later in this course).
Home Networking and WLANs (Wireless Local Area Networks)
A WLAN is a LAN based on Wi-Fi, a wireless network technology. Residences typically use a single LAN and connect to the Internet WAN via an ISP, using a broadband modem. The broadband modem is a device which makes a connection to the ISP over a high speed/high data volume cable connection. The ISP provides a WAN IP address to the modem, and all the computers participating in the home network use LAN (or private) IP addresses.
All the computers on the home LAN can communicate directly with each other, but must have their communications routed through a central gateway, typically a broadband router, to reach the ISP.
The individual computers within the home are increasingly connecting to the Internet (i.e. accessing the broadband modem) via a wireless router. This means that the LAN of the home can be referred to as a WLAN.
Free WLAN Connection
In the 21st century, many commercial businesses and community centres (e.g. libraries etc.) now offer their customers free limited wireless access, to encourage users who need to work remotely, to do so from their premises while enjoying their meals and beverages. For example, both Starbucks Coffee and McDonalds Restaurants now offer free wireless connections to users, as this is seen as an important value added service in the modern world.
